Syntheses of Acridines and Quinazoline-2,4(1H,3H)-dithiones by Rearrangements of N-Heterocyclic Carbenes of Indazole
摘要:
N-Heterocyclic carbenes of indazole which are arylated at N1 (1-aryl-indazol-3-ylidenes) have been generated by deprotonation of the corresponding indazolium salts. On deprotonation with potassium carbonate, potassium phosphate or tert-butanolate in dioxane or toluene at reflux temperature, a rearrangement to acridines took place. Deprotonation with n-butyllithium in THF at room temperature in the presence of carbon disulfide gave quinazoline-2,4(1H,3H)-dithiones by a new rearrangement reaction.
Copper Powder–Catalyzed C-N Bond Formation of Arylhydrazones of 2-Bromobenzaldehydes Leading to 1-Aryl-1H-indazoles
摘要:
Arylhydrazones of 2-bromobenzaldehydes and its analogs are cyclized in PEG-400 at 110 degrees C in the presence of a catalytic amount of copper powder along with NaOtBu to give 1-aryl-1H-indazole derivatives in good yields.
Abstract A simple and efficient strategy for the C–N cross-coupling of indazole with a variety of substituted arylbromides is reported. Under the optimized conditions, a broad scope of N-arylated products were obtained in good to excellent yields (up to 87%) under the ligand-free conditions.
Syntheses of Acridines and Quinazoline-2,4(1H,3H)-dithiones by Rearrangements of N-Heterocyclic Carbenes of Indazole
作者:Andreas Schmidt、Zong Guan、Mimoza Gjikaj
DOI:10.3987/com-14-13082
日期:——
N-Heterocyclic carbenes of indazole which are arylated at N1 (1-aryl-indazol-3-ylidenes) have been generated by deprotonation of the corresponding indazolium salts. On deprotonation with potassium carbonate, potassium phosphate or tert-butanolate in dioxane or toluene at reflux temperature, a rearrangement to acridines took place. Deprotonation with n-butyllithium in THF at room temperature in the presence of carbon disulfide gave quinazoline-2,4(1H,3H)-dithiones by a new rearrangement reaction.
Copper Powder–Catalyzed C-N Bond Formation of Arylhydrazones of 2-Bromobenzaldehydes Leading to 1-Aryl-1<i>H</i>-indazoles
作者:Hye Kyung Lee、Chan Sik Cho
DOI:10.1080/00397911.2011.614714
日期:2013.2.1
Arylhydrazones of 2-bromobenzaldehydes and its analogs are cyclized in PEG-400 at 110 degrees C in the presence of a catalytic amount of copper powder along with NaOtBu to give 1-aryl-1H-indazole derivatives in good yields.